Sebastiaan gave me a link to an interesting article by Michio Kaku about the physics of advanced alien civilizations (here’s a PDF in case the link doesn’t work) and how far we are of becoming an advanced civilization.

Kaku asks himself the question “How advanced could they possibly be?” and answers it in this article. He divides civilizations in different types: Type I, II, and III, which have mastered planetary, stellar and galactic forms of energy, respectively. Earth’s society is a Type 0 civilization currently and he expects us to reach level I in about 200 years. Read this article only if you’re interested in planets!